Move to callback for session tickets

This commit is contained in:
Manuel Pégourié-Gonnard 2015-05-19 15:28:00 +02:00
parent 2ff873c0fa
commit d59675d92c
6 changed files with 257 additions and 132 deletions

View file

@ -563,9 +563,6 @@ typedef struct mbedtls_ssl_session mbedtls_ssl_session;
typedef struct mbedtls_ssl_context mbedtls_ssl_context;
typedef struct mbedtls_ssl_transform mbedtls_ssl_transform;
typedef struct mbedtls_ssl_handshake_params mbedtls_ssl_handshake_params;
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
typedef struct mbedtls_ssl_ticket_keys mbedtls_ssl_ticket_keys;
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
typedef struct mbedtls_ssl_key_cert mbedtls_ssl_key_cert;
#endif
@ -750,20 +747,6 @@ struct mbedtls_ssl_handshake_params
#endif
};
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
/*
* Parameters needed to secure session tickets
*/
struct mbedtls_ssl_ticket_keys
{
unsigned char key_name[16]; /*!< name to quickly discard bad tickets */
mbedtls_aes_context enc; /*!< encryption context */
mbedtls_aes_context dec; /*!< decryption context */
unsigned char mac_key[16]; /*!< authentication key */
uint32_t ticket_lifetime;
};
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
/*
* List of certificate + private key pairs
@ -844,6 +827,15 @@ typedef struct
void *p_cookie; /*!< context for the cookie callbacks */
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
/** Callback to create & write a session ticket */
int (*f_ticket_write)( void *, const mbedtls_ssl_session *,
unsigned char *, const unsigned char *, size_t *, uint32_t * );
/** Callback to parse a session ticket into a session structure */
int (*f_ticket_parse)( void *, mbedtls_ssl_session *, unsigned char *, size_t);
void *p_ticket; /*!< context for the ticket callbacks */
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_ssl_key_cert *key_cert; /*!< own certificate/key pair(s) */
mbedtls_x509_crt *ca_chain; /*!< trusted CAs */
@ -870,10 +862,6 @@ typedef struct
const char **alpn_list; /*!< ordered list of protocols */
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_keys *ticket_keys; /*!< keys for ticket encryption */
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
/*
* Numerical settings (int then char)
*/
@ -1334,6 +1322,76 @@ void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl,
void (*f_set_timer)(void *, uint32_t int_ms, uint32_t fin_ms),
int (*f_get_timer)(void *) );
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
/**
* \brief Callback type: generate and write session ticket
*
* \note This describes what a callback implementation should do.
* This callback should generate and encrypted and
* authenticated ticket for the session and write it to the
* output buffer. Here, ticket means the opaque ticket part
* of the NewSessionTicket structure of RFC 5077.
*
* \param p_ticket Context for the callback
* \param session SSL session to bo written in the ticket
* \param start Start of the outpur buffer
* \param end End of the output buffer
* \param tlen On exit, holds the length written
* \param lifetime On exit, holds the lifetime of the ticket in seconds
*
* \return 0 if successful, or
* a specific MBEDTLS_ERR_XXX code.
*/
typedef int mbedtls_ssl_ticket_write_t( void *p_ticket,
const mbedtls_ssl_session *session,
unsigned char *start,
const unsigned char *end,
size_t *tlen,
uint32_t *lifetime );
/**
* \brief Callback type: parse and load session ticket
*
* \note This describes what a callback implementation should do.
* This callback should parse a session ticket as generated
* by the corresponding mbedtls_ssl_ticket_write_t function,
* and, if the ticket is authentic and valid, load the
* session.
*
* \note The implementation is allowed to modify the first len
* of the input buffer, eg to use it as a temporary area for
* the decrypted ticket contents.
*
* \param p_ticket Context for the callback
* \param session SSL session to be loaded
* \param buf Start of the buffer containing the ticket
* \param len Length of the ticket.
*
* \return 0 if successful, or
* MBEDTLS_ERR_SSL_INVALID_MAC if not authentic, or
* MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED if expired, or
* any other non-zero code for other failures.
*/
typedef int mbedtls_ssl_ticket_parse_t( void *p_ticket,
mbedtls_ssl_session *session,
unsigned char *buf,
size_t len );
/**
* \brief Configure SSL session ticket callbacks
*
* \param conf SSL configuration context
* \param f_ticket_write Callback for writing a ticket
* \param f_ticket_parse Callback for parsing a ticket
* \param p_ticket Context shared by the two callbacks
*/
void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf,
mbedtls_ssl_ticket_write_t *f_ticket_write,
mbedtls_ssl_ticket_parse_t *f_ticket_parse,
void *p_ticket );
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
/**
* \brief Set client's transport-level identification info.
@ -2008,15 +2066,6 @@ void mbedtls_ssl_conf_cbc_record_splitting( mbedtls_ssl_config *conf, char split
* or a specific error code (server only).
*/
int mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets );
/**
* \brief Set session ticket lifetime (server only)
* (Default: MBEDTLS_SSL_DEFAULT_TICKET_LIFETIME (86400 secs / 1 day))
*
* \param conf SSL configuration
* \param lifetime session ticket lifetime
*/
void mbedtls_ssl_conf_session_ticket_lifetime( mbedtls_ssl_config *conf, int lifetime );
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_RENEGOTIATION)

View file

@ -30,19 +30,69 @@
extern "C" {
#endif
/* Temporary, WIP */
int mbedtls_ssl_ticket_write( void *p_ticket,
const mbedtls_ssl_session *session,
unsigned char *start,
const unsigned char *end,
size_t *tlen,
uint32_t *ticket_lifetime );
/* Temporary, WIP */
int mbedtls_ssl_ticket_parse( void *p_ticket,
mbedtls_ssl_session *session,
unsigned char *buf,
size_t len );
/**
* \brief Context for session ticket handling functions
*/
typedef struct
{
unsigned char key_name[16]; /*!< name to quickly reject bad tickets */
mbedtls_aes_context enc; /*!< encryption context */
mbedtls_aes_context dec; /*!< decryption context */
unsigned char mac_key[16]; /*!< authentication key */
uint32_t ticket_lifetime; /*!< lifetime of tickets in seconds */
/** Callback for getting (pseudo-)random numbers */
int (*f_rng)(void *, unsigned char *, size_t);
void *p_rng; /*!< context for the RNG function */
}
mbedtls_ssl_ticket_context;
/**
* \brief Initialize a ticket context.
* (Just make it ready for mbedtls_ssl_ticket_setup()
* or mbedtls_ssl_ticket_free().)
*
* \param ctx Context to be initialized
*/
void mbedtls_ssl_ticket_init( mbedtls_ssl_ticket_context *ctx );
/**
* \brief Prepare context to be actually used
*
* \param ctx Context to be set up
* \param f_rng RNG callback function
* \param p_rng RNG callback context
* \param lifetime Tickets lifetime in seconds
*
* \return 0 is successful,
* or a specific MBEDTLS_ERR_XXX error code
*/
int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
uint32_t lifetime );
/**
* \brief Implementation of the ticket write callback
*
* \note See \c mbedlts_ssl_ticket_write_t for description
*/
mbedtls_ssl_ticket_write_t mbedtls_ssl_ticket_write;
/**
* \brief Implementation of the ticket parse callback
*
* \note See \c mbedlts_ssl_ticket_parse_t for description
*/
mbedtls_ssl_ticket_parse_t mbedtls_ssl_ticket_parse;
/**
* \brief Free a context's content and zeroize it.
*
* \param ctx Context to be cleaned up
*/
void mbedtls_ssl_ticket_free( mbedtls_ssl_ticket_context *ctx );
#ifdef __cplusplus
}

View file

@ -413,8 +413,11 @@ static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
int ret;
mbedtls_ssl_session session;
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
if( ssl->conf->f_ticket_parse == NULL ||
ssl->conf->f_ticket_write == NULL )
{
return( 0 );
}
/* Remember the client asked us to send a new ticket */
ssl->handshake->new_session_ticket = 1;
@ -435,11 +438,18 @@ static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
/*
* Failures are ok: just ignore the ticket and proceed.
*/
if( ( ret = mbedtls_ssl_ticket_parse( ssl->conf->ticket_keys, &session,
buf, len ) ) != 0 )
if( ( ret = ssl->conf->f_ticket_parse( ssl->conf->p_ticket, &session,
buf, len ) ) != 0 )
{
mbedtls_ssl_session_free( &session );
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret );
if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is not authentic" ) );
else if( ret == MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED )
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is expired" ) );
else
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret );
return( 0 );
}
@ -3525,7 +3535,7 @@ static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl )
* 10 . 9+n ticket content
*/
if( ( ret = mbedtls_ssl_ticket_write( ssl->conf->ticket_keys,
if( ( ret = ssl->conf->f_ticket_write( ssl->conf->p_ticket,
ssl->session_negotiate,
ssl->out_msg + 10,
ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN,

View file

@ -39,6 +39,56 @@
#include <string.h>
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
/*
* Initialze context
*/
void mbedtls_ssl_ticket_init( mbedtls_ssl_ticket_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_ssl_ticket_context ) );
}
/*
* Setup context for actual use
*/
int mbedtls_ssl_ticket_setup( mbedtls_ssl_ticket_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
uint32_t lifetime )
{
int ret;
unsigned char buf[16];
ctx->f_rng = f_rng;
ctx->p_rng = p_rng;
ctx->ticket_lifetime = lifetime;
mbedtls_aes_init( &ctx->enc );
mbedtls_aes_init( &ctx->dec );
if( ( ret = f_rng( p_rng, ctx->key_name, 16 ) != 0 ) ||
( ret = f_rng( p_rng, ctx->mac_key, 16 ) != 0 ) ||
( ret = f_rng( p_rng, buf, 16 ) != 0 ) )
{
return( ret );
}
if( ( ret = mbedtls_aes_setkey_enc( &ctx->enc, buf, 128 ) ) != 0 ||
( ret = mbedtls_aes_setkey_dec( &ctx->dec, buf, 128 ) ) != 0 )
{
mbedtls_ssl_ticket_free( ctx );
return( ret );
}
mbedtls_zeroize( buf, sizeof( buf ) );
return( 0 );
}
/*
* Serialize a session in the following format:
* 0 . n-1 session structure, n = sizeof(mbedtls_ssl_session)
@ -170,7 +220,7 @@ int mbedtls_ssl_ticket_write( void *p_ticket,
uint32_t *ticket_lifetime )
{
int ret;
mbedtls_ssl_ticket_keys *ctx = p_ticket;
mbedtls_ssl_ticket_context *ctx = p_ticket;
unsigned char *p = start;
unsigned char *state;
unsigned char iv[16];
@ -194,7 +244,8 @@ int mbedtls_ssl_ticket_write( void *p_ticket,
p += 16;
/* Generate and write IV (with a copy for aes_crypt) */
memset( p, 0x2a, 16 ); /* Temporary WIP */
if( ( ret = ctx->f_rng( ctx->p_rng, p, 16 ) ) != 0 )
return( ret );
memcpy( iv, p, 16 );
p += 16;
@ -244,7 +295,7 @@ int mbedtls_ssl_ticket_parse( void *p_ticket,
size_t len )
{
int ret;
mbedtls_ssl_ticket_keys *ctx = p_ticket;
mbedtls_ssl_ticket_context *ctx = p_ticket;
unsigned char *key_name = buf;
unsigned char *iv = buf + 16;
unsigned char *enc_len_p = iv + 16;
@ -317,4 +368,15 @@ int mbedtls_ssl_ticket_parse( void *p_ticket,
return( 0 );
}
/*
* Free context
*/
void mbedtls_ssl_ticket_free( mbedtls_ssl_ticket_context *ctx )
{
mbedtls_aes_free( &ctx->enc );
mbedtls_aes_free( &ctx->dec );
mbedtls_zeroize( ctx, sizeof( mbedtls_ssl_ticket_context ) );
}
#endif /* MBEDTLS_SSL_TICKET_C */

View file

@ -5146,56 +5146,6 @@ int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl )
return( 0 );
}
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static void ssl_ticket_keys_free( mbedtls_ssl_ticket_keys *tkeys )
{
mbedtls_aes_free( &tkeys->enc );
mbedtls_aes_free( &tkeys->dec );
mbedtls_zeroize( tkeys, sizeof(mbedtls_ssl_ticket_keys) );
}
/*
* Allocate and initialize ticket keys
*/
static int ssl_ticket_keys_init( mbedtls_ssl_config *conf )
{
int ret;
mbedtls_ssl_ticket_keys *tkeys;
unsigned char buf[16];
if( conf->ticket_keys != NULL )
return( 0 );
tkeys = mbedtls_malloc( sizeof(mbedtls_ssl_ticket_keys) );
if( tkeys == NULL )
return( MBEDTLS_ERR_SSL_MALLOC_FAILED );
mbedtls_aes_init( &tkeys->enc );
mbedtls_aes_init( &tkeys->dec );
/* Temporary WIP! Using hardcoded keys. This is to remove the dependency
* on the RNG and allow puttint the keys in conf. Key generation will soon
* be move outside the main SSL module anyway. */
memset( tkeys->key_name, 'x', 16 );
memset( tkeys->mac_key, 0x2a, 16 );
memset( buf, 0x2a, 16 );
if( ( ret = mbedtls_aes_setkey_enc( &tkeys->enc, buf, 128 ) ) != 0 ||
( ret = mbedtls_aes_setkey_dec( &tkeys->dec, buf, 128 ) ) != 0 )
{
ssl_ticket_keys_free( tkeys );
mbedtls_free( tkeys );
return( ret );
}
conf->ticket_keys = tkeys;
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
/*
* SSL set accessors
*/
@ -5691,20 +5641,17 @@ int mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets
{
conf->session_tickets = use_tickets;
#if defined(MBEDTLS_SSL_CLI_C)
if( conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
return( 0 );
#endif
if( use_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
return( 0 );
return( ssl_ticket_keys_init( conf ) );
return( 0 );
}
void mbedtls_ssl_conf_session_ticket_lifetime( mbedtls_ssl_config *conf, int lifetime )
void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf,
mbedtls_ssl_ticket_write_t *f_ticket_write,
mbedtls_ssl_ticket_parse_t *f_ticket_parse,
void *p_ticket )
{
conf->ticket_keys->ticket_lifetime = lifetime;
conf->f_ticket_write = f_ticket_write;
conf->f_ticket_parse = f_ticket_parse;
conf->p_ticket = p_ticket;
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
@ -6699,11 +6646,6 @@ int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf,
conf->cbc_record_splitting = MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED;
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
ssl_ticket_keys_init( &conf );
conf->ticket_keys->ticket_lifetime = MBEDTLS_SSL_DEFAULT_TICKET_LIFETIME;
#endif
#if defined(MBEDTLS_SSL_SET_CURVES)
conf->curve_list = mbedtls_ecp_grp_id_list( );
#endif
@ -6765,14 +6707,6 @@ void mbedtls_ssl_config_free( mbedtls_ssl_config *conf )
}
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
if( conf->ticket_keys )
{
ssl_ticket_keys_free( conf->ticket_keys );
mbedtls_free( conf->ticket_keys );
}
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
ssl_key_cert_free( conf->key_cert );
#endif

View file

@ -69,6 +69,10 @@ int main( void )
#include "mbedtls/ssl_cache.h"
#endif
#if defined(MBEDTLS_SSL_TICKET_C)
#include "mbedtls/ssl_ticket.h"
#endif
#if defined(MBEDTLS_SSL_COOKIE_C)
#include "mbedtls/ssl_cookie.h"
#endif
@ -114,7 +118,7 @@ int main( void )
#define DFL_MFL_CODE MBEDTLS_SSL_MAX_FRAG_LEN_NONE
#define DFL_TRUNC_HMAC -1
#define DFL_TICKETS MBEDTLS_SSL_SESSION_TICKETS_ENABLED
#define DFL_TICKET_TIMEOUT -1
#define DFL_TICKET_TIMEOUT 86400
#define DFL_CACHE_MAX -1
#define DFL_CACHE_TIMEOUT -1
#define DFL_SNI NULL
@ -190,7 +194,7 @@ int main( void )
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#define USAGE_TICKETS \
" tickets=%%d default: 1 (enabled)\n" \
" ticket_timeout=%%d default: ticket default (1d)\n"
" ticket_timeout=%%d default: 86400 (one day)\n"
#else
#define USAGE_TICKETS ""
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
@ -740,6 +744,9 @@ int main( int argc, char *argv[] )
#if defined(MBEDTLS_SSL_CACHE_C)
mbedtls_ssl_cache_context cache;
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_context ticket_ctx;
#endif
#if defined(SNI_OPTION)
sni_entry *sni_info = NULL;
#endif
@ -778,6 +785,9 @@ int main( int argc, char *argv[] )
#if defined(MBEDTLS_SSL_CACHE_C)
mbedtls_ssl_cache_init( &cache );
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_init( &ticket_ctx );
#endif
#if defined(MBEDTLS_SSL_ALPN)
memset( (void *) alpn_list, 0, sizeof( alpn_list ) );
#endif
@ -1584,14 +1594,21 @@ int main( int argc, char *argv[] )
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
if( ( ret = mbedtls_ssl_conf_session_tickets( &conf, opt.tickets ) ) != 0 )
if( opt.tickets == MBEDTLS_SSL_SESSION_TICKETS_ENABLED )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_conf_session_tickets returned %d\n\n", ret );
goto exit;
}
if( ( ret = mbedtls_ssl_ticket_setup( &ticket_ctx,
mbedtls_ctr_drbg_random, &ctr_drbg,
opt.ticket_timeout ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_ticket_setup returned %d\n\n", ret );
goto exit;
}
if( opt.ticket_timeout != -1 )
mbedtls_ssl_conf_session_ticket_lifetime( &conf, opt.ticket_timeout );
mbedtls_ssl_conf_session_tickets_cb( &conf,
mbedtls_ssl_ticket_write,
mbedtls_ssl_ticket_parse,
&ticket_ctx );
}
#endif
#if defined(MBEDTLS_SSL_PROTO_DTLS)
@ -2203,6 +2220,9 @@ exit:
#if defined(MBEDTLS_SSL_CACHE_C)
mbedtls_ssl_cache_free( &cache );
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
mbedtls_ssl_ticket_free( &ticket_ctx );
#endif
#if defined(MBEDTLS_SSL_COOKIE_C)
mbedtls_ssl_cookie_free( &cookie_ctx );
#endif